Ruyan Guo (left), a UTSA professor, attempts to get an electrical reading as student Noah Mohammed watches. Guo is part of a team at UTSA that invented a “nanorobot” particle. Photo by Billy Calzada / Express-News Staff Photographer

By S.M. Chavey STAFF WRITER, San Antonio Express-News

A team of scientists at the University of Texas at San Antonio invented a minuscule, robotlike particle that can be directed by remote control to enter a human cell.

The particle, a “nanorobot,” has potential as a tool in fighting disease. For example, it could eventually deliver medicine to a cancerous cell and be steered away from a healthy one, according to the researchers.

The robot has not yet been tried on humans, but it has entered live human cells.

“Usually, when you see a robot, you say, ‘Where is the arm, leg, head?’ ” said Ruyan Guo, a professor in UTSA’s electrical and computer engineering department who was part of the team. “This one really doesn’t have visible hands or legs yet, but it can move and function as if it had all those things.”

At about 120 nanometers thick, the robot is equivalent to one-thousandth the thickness of a strand of hair, said Amar S. Bhalla, another team member and a professor in the department.

By comparison, most tiny medical robots are measured in millimeters, one of which is a million times larger than a nanometer.

The nanoparticle has a core made of cobalt ferrite and a coating layer “shell” of barium titanate. It can be moved by remote control using an electromagnetic field.

“It can penetrate the channel of the membrane of the cell so that it can enter into a small object, in this case, a biological cell,” Guo said. “It’s like a robot that can enter into a room. This is not entering a room, it’s entering a cell. A biological cell, which is very small.”

The nanorobot can also transport cells from one position to another and realign them, just as larger robots are able to push objects or shovel them, she said.

Its microscopic size is key to the robot’s potential in treating disease in the future.

It could have a role in targeted delivery of drugs “so that only the bad part of the tissues can be attacked, whereas the rest of the tissue would not be affected,” Bhalla said. Cancer patients could avoid the damaging side effects of some existing treatments that spread throughout the body.

The nanorobot is not strong enough to carry even a microgram, which is one-millionth of a gram, he said. So the researchers envision an army of nanorobots — as few as a couple hundred and as many as 10,000, if needed — entering the body to target cells.

The professors credited another team member, UTSA doctoral student Soutik Betal, for his substantial contributions to the project. The nanoparticles were built in 2015, and the robot’s functionality was demonstrated in late 2016.

This year, the seven-member team had its paper about the robot published in the peer-reviewed journal Scientific Reports.

Soon after, they learned they had earned a spot in Guinness World Records for smallest medical robot.

“You are officially amazing,” Guo said they were told when receiving the certificate.

A spokeswoman for Guinness World Records said there was no such record or category previously.

On its website, Guinness World Records calls itself the unrivaled authority on records, with 40,000 in its database.

Professor Alessandro Grattoni, chairman of the nanomedicine department at the Houston Methodist Research Institute, said he had not heard of any other Guinness-sanctioned record in the nanomedicine field.

Researchers elsewhere have been developing similar nanoparticles but have not previously used the term “robot” to describe them, Grattoni said when asked to comment on the paper, which he had no role in. He hesitated to call the nanoparticle a robot because it requires remote manipulation and could not autonomously find problem tissues or tumors, but he complimented the research.

“This technology is an interesting development in multifunctional nanoparticles,” Grattoni wrote in an email.

“I cannot readily see immediate applicability in the clinical setting. The work is at an early stage, and a thorough and systematic analysis of its potential preclinical applications would be needed even before moving forward toward clinical translation,” he added.

The UTSA scientists did not set out to create a robot but stumbled onto it through their research, which is partially funded by the National Science Foundation and the Defense Department.

Guo said she would like to see the nanorobot technology become available to humans within the next decade. The timeline depends on how many other researchers get involved and how much financial backing the UTSA researchers get, among other factors. The Food and Drug Administration has stringent regulations and requires substantial testing before new medical devices and procedures reach humans.

The researchers said they hope that the recent article and the Guinness record will encourage more competition and attract financial resources to further their research. They said they are applying for patents and that companies are interested in investing in the technology.

“This is really just a beginning of a new adventure,” Guo said.

The team is continuing to research other uses for the nanorobot, including repairing and realigning neuron cells to recover functionality in patients with Alzheimer’s and other memory-loss diseases.

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